Hardware design and verification techniques for Giga-bit Forward-Error Correction systems on FPGAs

Abstract

Contemporary and next-generation wireless, wired and optical telecommunication systems rely on sophisticated forward error-correction (FEC) schemes to facilitate operation at particularly low Bit Error Rate (BER). The ever increasing demand for high information throughput rate, combined with requirements for moderate cost and low-power operation, renders the design of FEC systems a challenging task. The definition of the parity check matrix of an LDPC code is a crucial task as it defines both the computational complexity of the decoder and the error correction capabilities. However, the characterization of the corresponding code at low BER is a computationally intensive task that cannot be carried out with software simulation. We here demonstrate procedures that involve hardware acceleration to facilitate code design. In addition to code design, verification of operation at low BER requires strategies to prove correct operation of hardware, thus rendering FPGA prototyping a necessity. This paper demonstrates design techniques and verification strategies that allow proof of operation of a gigabit-rate FEC system at low BER, exploiting the state-of-the-art Virtex-7 technology. It is shown that by occupying up to 70% - 80% percent of slices on a Virtex-7 XC7V485T device, iterative decoding at gigabit rate can be verified.